let age1 = 18
let name1 = "zs"
let isOK:boolean
console.log(typeof age1)
console.log(typeof name1)
console.log(name1.toUpperCase())

name1="LIST"
isOK = false
function changeNameToUpper1(xxx:string):string{
    let a = xxx.toUpperCase()
    return a
}

let xx=function(a:number,b:number):number{
 return a+b
}
let mm=(a:number,b:number):number=>{
 return a+b
}
let yy: (a:number,b:number)=>number = (a:number,b:number):number=>{
 return a+b
}
let result1 = xx(5, 3);       
let result2 = mm(10, 20);     
let result3 = yy(7, 8); 
console.log(result1)
console.log(result2)
console.log(result3)



let res3 =changeNameToUpper1(name1)
console.log(res3)


let res2 = changeNameToUpper1("hello")
console.log(res2)